Update README.md to include comprehensive documentation for ThinkPHP 8, featuring installation instructions, new features, sponsorship details, and links to resources.

app/middleware.php

@@ -0,0 +1,10 @@
+<?php
+// 全局中间件定义文件
+return [
+    // 全局请求缓存
+    // \think\middleware\CheckRequestCache::class,
+    // 多语言加载
+    // \think\middleware\LoadLangPack::class,
+    // Session初始化
+    // \think\middleware\SessionInit::class
+];